Accucraft live steam Mogul

Fred2179G

Fred2179G

Registered
20 Apr 2017
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Someone suggested to me to watch for escaping steam. While the loco is pre-heating there is only a little smoke I assume travelling up the stack but when running there is a subsstantial amount out of the stack.
Brian
I think that was me. Smoke while heating is usually blue/grey and is oil burning out of the smokebox - Accu locos are renowned for throwing excess oil. When running, it is supposed to come out of the stack BUT only during the exhaust 'event'. You can observe these at low speed - there should be 4 distinct puffs as per a real engine.

What we found on an 0-6-0 was that steam was coming out when it wasn't supposed to, If you have lots of steam exhausting, it could be 'blowing by' the valves or pistons and being wasted.
 
B

BRIAN

Registered
18 Sep 2019
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Ontario
I think that was me. Smoke while heating is usually blue/grey and is oil burning out of the smokebox - Accu locos are renowned for throwing excess oil. When running, it is supposed to come out of the stack BUT only during the exhaust 'event'. You can observe these at low speed - there should be 4 distinct puffs as per a real engine.

What we found on an 0-6-0 was that steam was coming out when it wasn't supposed to, If you have lots of steam exhausting, it could be 'blowing by' the valves or pistons and being wasted.
I will pay attention to the timing of the steam exhaust. I am glad to hear that the small amount of smoke is normal. It is funny ... as a model railroader for many years I knew that there were 4 chuffs per revolution of the drivers but didn't consider it in the model.
Brian
 
maxi-model

maxi-model

UK/US/ROW steam narrow gauge railways 1:1
27 Oct 2009
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Bucks/Oxon/Northants area
As Fred says it is normal to see a little smoke during the warm up phase as steam oil residue inside the smokebox burns off. However if this is persistent then it might indicate other issues. Cracking open the smokebox door on an Accucraft loco at light up for a couple of minutes is almost a ritual for me.

My Accucraft C-19 recently failed due, as it turned out, to a failed soldered joint on a nut, that seemingly acted a "stopper on one end the superheater tube (the nut writing this was at the other end :) ). It had the service engineer scratching his head initially when I took the loco to him as he had not seen this type of failure before.There were suggestions if the worst diagnosis came true I might be writing a largeish cheque for a fix. Let me recount how the symptoms manifested themselves before the final failure and need for repair.

I tend to use my locos infrequently so I'm in the habit of going through one or two basics before running. I had noticed my C-19 was not "pulling" quite as well as it had in the past. So I did all the usual things to check the gas supply and R/C operation of the regulator and reverser. I had oiled around and made sure all reservoirs were full and then checked for any obvious binding in the wheels and motions. I had noticed though a little seepage of steam from where I didn't expect it for some time but hadn't given that a second thought as the loco had been running well up till then. I ran the loco again, still not great, so I opened up the smokebox door and noticed that a forked blue, not a billow of yellow signifying unburnt gas, flame was showing proud of the end of the boiler/burner tube. Not normal, the flame should have "popped back" and be fully contained in the fire tube. So I shut down the loco and tried to relight. The superheater tube at this point was glowing red hot (probably what you are looking at down the smoke stack), which I was told subsequently was not abnormal. Tried to relight it and that is where I started to have problems with the burner going out repeatedly as soon as the boiler had raised just a few lbs of pressure and when I opened the regulator. I also noticed that what I thought was oil burn off turned out to be paint inside the smokebox being, shall we say, overheated and when I opened the smoke box door that forked blue flame, projecting out of the fire tube, was back again.

Off the the trusty service engineer, problem fixed for a fee of £60. I can only relate my experiences and see if some of it resonates with others. Max

P.S. I really need an editor :D
 
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Fred2179G

Fred2179G

Registered
20 Apr 2017
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USA
he flame should have "popped back" and be fully contained in the fire tube. So I shut down the loco and tried to relight. The superheater tube at this point was glowing red hot (probably what you are looking at down the smoke stack), which I was told subsequently was not abnormal.
Max, it is abnormal to see the tube glowing red hot inside the smokebox down the chimney/stack. The tube runs through the flue (yes, I know you know that but maybe Brian doesn't,) next to the burner, and will get red hot inside the flue.
If it's red hot in the smokebox then you have a problem - as you described. Not sure why your C-19 was not popping back to the burner. Your steam leak was perhaps caused by the solder on the nut on the pipe being hot enough to melt.

Brian, making the superheater red hot is intended to superheat the steam inside that is in its way to the cylinders, which it does. However, as Accucraft locos have lots of oil in the steam, that oil can burn in the tube and hence produce a semi-blockage. (A full blockage would be too easy to diagnose!)
That superheater tube is not easy to remove but it can be done. It's attached at each end with a nut and ferrule (compression sleeve) and the latter is usually silver-soldered to the pipe. You remove the burner with the 2 bolts on the outer flange (which may mean dismantling something else to get access) and pull it out. In the bottom of the smokebox you can usually see (dental mirror?) where the nut attaches it to the cylinder block. In the cab it is attached to the throttle manifold.
You may not be able to remove it without bending which I do not recommend. However, once it is loose you can test to see if it is blocked. Or you can find someone with the equipment to make a new one and fit it.
 
B

BRIAN

Registered
18 Sep 2019
17
2
70
Ontario
As Fred says it is normal to see a little smoke during the warm up phase as steam oil residue inside the smokebox burns off. However if this is persistent then it might indicate other issues. Cracking open the smokebox door on an Accucraft loco at light up for a couple of minutes is almost a ritual for me.

My Accucraft C-19 recently failed due, as it turned out, to a failed soldered joint on a nut, that seemingly acted a "stopper on one end the superheater tube (the nut writing this was at the other end :) ). It had the service engineer scratching his head initially when I took the loco to him as he had not seen this type of failure before.There were suggestions if the worst diagnosis came true I might be writing a largeish cheque for a fix. Let me recount how the symptoms manifested themselves before the final failure and need for repair.

I tend to use my locos infrequently so I'm in the habit of going through one or two basics before running. I had noticed my C-19 was not "pulling" quite as well as it had in the past. So I did all the usual things to check the gas supply and R/C operation of the regulator and reverser. I had oiled around and made sure all reservoirs were full and then checked for any obvious binding in the wheels and motions. I had noticed though a little seepage of steam from where I didn't expect it for some time but hadn't given that a second thought as the loco had been running well up till then. I ran the loco again, still not great, so I opened up the smokebox door and noticed that a forked blue, not a billow of yellow signifying unburnt gas, flame was showing proud of the end of the boiler/burner tube. Not normal, the flame should have "popped back" and be fully contained in the fire tube. So I shut down the loco and tried to relight. The superheater tube at this point was glowing red hot (probably what you are looking at down the smoke stack), which I was told subsequently was not abnormal. Tried to relight it and that is where I started to have problems with the burner going out repeatedly as soon as the boiler had raised just a few lbs of pressure and when I opened the regulator. I also noticed that what I thought was oil burn off turned out to be paint inside the smokebox being, shall we say, overheated and when I opened the smoke box door that forked blue flame, projecting out of the fire tube, was back again.

Off the the trusty service engineer, problem fixed for a fee of £60. I can only relate my experiences and see if some of it resonates with others. MaxThis

P.S. I really need an editor :D
This is sounding very familiar to me. Like I have said I remember questioning this red hot item ( I thought it was a blockage in the flue |) and it turned out to be the super heater. I don.t recall seeing it recently though. I will also try watching the chuffs to make sure there are the 4 exhausts per revolution .
I have a lot of difficulty keeping the burning going some times and other times I might have to relight it many times. There is always that little whiff of blue smoke while heating up though along with the usual popping. I can't thank all of you for your input into this.. much appreciated.
Brian
 
Fred2179G

Fred2179G

Registered
20 Apr 2017
272
35
USA
This is sounding very familiar to me
Yeah, well, most Accucraft locos have the same basic construction, so when you've been fighting them for 20 years (I think my C-16 turned up in 2002,) and you read all these threads about issues and questions, you get to know what can go wrong.
 
beavercreek

beavercreek

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I have a C19 live steamer and had a lot of trouble with her when I first bought her as a used loco some years back.
The C19 does not have a lot of grunt anyway as the cylinders are just too small for the weight of the loco (and any cars it is pulling) but my one was finding it hard to pull the skin off a rice pudding (made a real mess of the tracks :D ).
I tried all of the things that Max has mentioned above and finally bit the bullet.
I had not stripped a live steamer loco down before but decided that it was the time.
To cut a long story short..I found that the superheater was practically full of burnt oil and was not passing enough steam through., thus the poor performance.
It had obviously been run too hot with the gas turned up too far or possibly had been been burning hot while stationary... that is the trouble with buying a second hand loco from someone you do not know...you never know how it was treated.
After a clean out of the super heater, I reassembled the loco (using the photos and video that I had taken of the dismantling) and then tested.. a completely different beast..... yes it was still underpowered so it could not take on the heavy gradients on my layout, but on a flat-ish track it was fine hauling two or three Accucraft freight or passenger stock.

I have just looked for the folder with the photos and video of the loco breakdown but can't find it!
 
maxi-model

maxi-model

UK/US/ROW steam narrow gauge railways 1:1
27 Oct 2009
4,617
180
Bucks/Oxon/Northants area
Agree about the superheater gunking up with baked on steam oil, too hot, too thick and too much. That's probably why my 3 cyl' Shay had an adjustable oiler - you slow the flow after a few minutes running. Blocked that one :D Likewise too much heat on my C-19 probably started the issues with the superheater pipe's securing nut desoldering - that's why I caution about too "warm" water in a gas tank bath. The two incedents are not unrelated ;) Max
 
Fred2179G

Fred2179G

Registered
20 Apr 2017
272
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USA
I have just looked for the folder with the photos and video of the loco breakdown but can't find it!
I have a complete set of photos as I took the boiler out of mine to swap the domes for some old-style ones (I backdated my C-19 to 1905, when the East Broad Top bought one when D&RGW didn't take delivery.) I'm not sure they'd help with a 2-6-0 Mogul though. My C-19 was new and has given me years of good running. (Video on Youtube, user Fred2179.)
Sounds like a superheater investigation is called for on Brian's loco.
 
B

BRIAN

Registered
18 Sep 2019
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Ontario
I have a complete set of photos as I took the boiler out of mine to swap the domes for some old-style ones (I backdated my C-19 to 1905, when the East Broad Top bought one when D&RGW didn't take delivery.) I'm not sure they'd help with a 2-6-0 Mogul though. My C-19 was new and has given me years of good running. (Video on Youtube, user Fred2179.)
Sounds like a superheater investigation is called for on Brian's loco.
It is certainly starting to sound like it is the super heater for sure. I am not the person to try repairing that though. I always tried to get the flame back to the rear of the fllue ( when it "pops" ) and not let it roar out of the firebox.

Brian
 
Fred2179G

Fred2179G

Registered
20 Apr 2017
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USA
It is certainly starting to sound like it is the super heater for sure. I am not the person to try repairing that though. I always tried to get the flame back to the rear of the fllue ( when it "pops" ) and not let it roar out of the firebox.
Having the fire in the smokebox doesn't affect the superheater tube - in fact, the tube is inside the flue and therefore won't even get any heat. But do make sure the flame pops back to the burner by looking down the flue after you have lit up. Then leave the smokebox door cracked until you decide to move.

It isn't tricky to loosen the superheater tube. It comes from the throttle body and goes in to the flue next to the burner. Some very small spanners will loosen the pipe nut at the top, and the burner is held in by 2 small screws. At the smokebox end, you need patience and the correct spanner to loosen the pipe nut. When both ends are out, you can rotate it a little so you can blow through it or add something to dissolve the gunk.

Max - what dissolves the burnt oil gunk?
 
beavercreek

beavercreek

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"Max - what dissolves the burnt oil gunk?"

I used a little of the stuff that you use to clean ovens.. very sparingly and not for long (I used a length of 2.5mm house mains electrical wire to 'scrape' the barrel